Right. That’s why, when you use real 2010 splits, Romney is doing well. By even unskewed data, he’s turning out a higher % of Rs than Zero is of Ds. Oh, and between the big voter roll purges and some impressive shifts in party ID since 2008, this simply is not the same electorate.
To start with the tendency is for less advantaged factions to abandon a winning party they're being frozen out of for a more favorably disposed losing party. These movements can take decades.
2012 is unlikely to be any better.
2012 will NOT be like 2010. Republican’s will not enjoy the same level of participation advantage.